The homeless man who pleaded guilty to fatally stabbing an Iowa State University golfer has been sentenced to life in prison without the possibility of parole.

District Judge Bethany Currie at the Story County Justice Center in Nevada handed down the punishment to Collin Richards. The 22-year-old man pleaded guilty to the first-degree murder of Celia Barquin Arozamena while she was golfing at the Coldwater Golf Links in Ames, Iowa, on Sept. 17.

Barquin Arozamena, a civil engineering student and decorated athlete, was 22 when she died.

Richards submitted a letter into court records earlier this month in which he promised to use all the resources available him to become a better person.

“I want to show remorse for stripping a life from society,” Richards wrote in a hand-written note filed in Story County district court. “I want the family and you to know I’m sorry.”

Police said Richards, who was staying at a homeless camp at the time of Barquin Arozamena's killing, told another man he had "an urge to rape and kill a woman" the day prior.

When Richards arrived on Sept. 17 at an acquaintance's house, he was disheveled and covered in blood, sand and water, a witness told detectives. Richards has had repeated run-ins with authorities beginning when he was 10 years old, court records show, including a history of mental illness and drug addiction that prompted more than two dozen juvenile and criminal charges.

A native of Puente San Miguel, in Spain, Barquin Arozamena has been remembered for her infectious smile and a bubbly personality. She was among the most accomplished golfers in Iowa State history recognized prior to her death as the 2018 Big 12 Conference women's golf champion and Iowa State Female Athlete of the Year.